1. Field of the Invention
The present invention relates to an insert-type rotary core mold apparatus for injection-molding articles having threads formed on inner surfaces thereof.
2. Description of the Prior Art
Conventional rotary core molds are of an integrated type in which a mold base and a cavity core section are combined during production, and there have been no insert-type rotary core molds. For this reason, it has been necessary to fabricate the overall rotary core mold according to each type of molding, and the cost of making molds has been high. In addition, it is necessary to replace the mold each time the type of molding is changed. However, since the weight of the mold is large, and that operation is not easy, there has been a drawback in that the replacement of the mold is time-consuming.